<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>Bootstrap 101 Template</title>

    <!-- Bootstrap -->
    <link href="css/bootstrap.min.css" rel="stylesheet">

    <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
    <!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
    <!--[if lt IE 9]>
    <script src="http://cdn.bootcss.com/html5shiv/3.7.2/html5shiv.min.js"></script>
    <script src="http://cdn.bootcss.com/respond.js/1.4.2/respond.min.js"></script>
    <![endif]-->
</head>
<body>

    <div class="input-group input-group-lg">
        <span class="input-group-addon" id="basic-addon1">用户名</span>
        <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">
    </div>
    <!--将提示放在不同位置，即可实现左右-->
    <br><br>
    <div class="input-group">
        <input type="text" class="form-control" placeholder="Recipient's username" aria-describedby="basic-addon2">
        <span class="input-group-addon" id="basic-addon2">@example.com</span>
    </div>
    <!--尺寸设定，在最外层的input-group 添加.input-group-lg sm xs
    <br><br>
    <div class="input-group input-group-sm">
        <span class="input-group-addon">$</span>
        <input type="text" class="form-control" aria-label="Amount (to the nearest dollar)">
        <span class="input-group-addon">.00</span>
    </div>

<!--jQuery库必须加载，而且必须在bootstrap.min.js之前-->
<!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
<script src="http://cdn.bootcss.com/jquery/1.11.3/jquery.min.js"></script>
<!-- Include all compiled plugins (below), or include individual files as needed -->
<script src="js/bootstrap.min.js"></script>
</body>
</html>